Figure 2. Aldosterone induces TRPM7-dependent Mg²⁺ influx in HEK-293 cells.

HEK-293 cells expressing WT hTRPM7 channels or the mutants ΔKinase (deleted kinase) and K1648R (inactive kinase) were loaded with Mag-FURA-2 and were stimulated with 100 nM aldosterone in the absence or presence of the MR antagonist eplerenone (10 μM). Changes in Mag-FURA-2 fluorescence were recorded (excitation ratio: 340/380 nm). (A) Bar graph, Mag-FURA-2 fluorescence ratio peak obtained after aldosterone stimulation. (B) Bar graph, Mag-FURA-2 fluorescence ratio peak obtained after aldosterone stimulation in the absence and in presence of eplerenone. Top panels, representative images of aldosterone effect on Mag-FURA-2 fluorescence intensity. Results are expressed as mean ± SE of 6-8 independent experiments.*p<0.05, versus corresponding basal levels; **p <0.05, aldosterone in the absence versus presence of eplerenone.